“Is my body shutting down?”

I'm a 15 year old girl, with around 45 kg of weight (haven't checked in a while) and quite short for my age, reaching 155 cm in height. I underwent starvation for almost four days straight, not eating or drinking in this period of time- I do not have anorexia, but I do have severe depression, diagnosed by a psychologist (history of medication is fluoxetine and metrobalism? I think- I don't remember but it was to treat better sleeping mostly) and have done this once before for almost three days.

I experienced before: headaches, some stomach issues, as well as my menstrual cycle being on then off for a few months- on again for 1-2 months and going again and has not returned since- it may be stress, I also vomited very little stomach acid (i think it was stomach acid anyways).

During the starvation, I felt fatigued and affected my brain, as in low concentration and all that, hunger pains and lower back pains. Now after the starvation (i am continuing eating) I feel stomach pains still and fatigue- though i felt a bit of fatigue before starvation- it increased- and is still going on. what should I do?